The present invention relates to a marking element for use in conjunction with a product which is required to be maintained under a particular temperature or temperature-time condition.
There any many products which need to be stored under conditions such that a particular temperature limit is not exceeded, or at least is not exceeded for longer than a predetermined time. For convenience, both of these conditions are referred to generically herein as the predefined temperature condition. Generally, the temperature limit will be a maximum (rather than a minimum) temperature.
Particular examples are certain types of food product that have been pre-cooked or processed by freezing, irradiation, partial cooking, freeze drying or steaming (or other food processing procedures). If such products are not stored in accordance with the pre-defined temperature conditions then there is the danger of contamination by organisms which are injurious to human health. This danger is not removed by subsequently storing the product below the temperature maximum. Further examples of products which may need to be stored in accordance with pre-defined temperature conditions are certain pharmaceuticals which would otherwise deteriorate.
Currently, the purchasers of such susceptible products are not able to determine whether the product has been stored in contravention of the pre-defined conditions. For example, frozen food purchased in, say, a supermarket may be adequately frozen at the time of sale but the purchaser is unable to tell whether the food has previously been incorrectly stored. This has the potential health disadvantages mentioned above.